Inflatable restraint devices, commonly called airbags, are standard equipment on most new vehicles. As consumer's concerns for safety have increased, additional airbags have been employed in different areas of the vehicle other than in the steering wheel and the passenger side of the instrument panel. Side curtain airbags have grown in popularity due to the lack of a crush zone and energy dissipation capacity in the sides of vehicles. Side curtain airbags have been employed or stored in areas of the roof rails and headliners or in the side doors. These airbag devices are typically concealed from occupant view by interior trim panels.
Interior trim panels concealing the air bag devices are a challenge for designers and engineers due to the competing interests of permitting the airbags to be easily deployed in the desired areas while maintaining aesthetic appeal of the vehicle passenger compartment. The trim panels must also be capable of enduring the explosive forces of air bag devices without being dislodged from the vehicular structure that they are attached to and potentially entering the passenger compartment. These challenges are accentuated in the front A-pillar area of vehicles due to the limited space and position proximate to the driver and front passenger.
Known trim panel and instrument panel designs for concealing air bag devices have included rupturable covers, for example, in steering wheel and passenger side frontal airbags deployable from the instrument panel as well as other interior trim panels. These devices have included so-called tethers or other devices which attempt to prevent the trim panel, or portions thereof, from detaching from their attachment points to the vehicle or a portion of the trim panel from breaking off and detaching under the explosive forces imparted by the airbag.
The known devices suffer from several disadvantages including the tethers being applied to the outer surface of the trim panel, i.e. the side toward the interior of the passenger compartment visible by the occupants, and use of separate straps providing a second or auxiliary attachment of the trim panel to the vehicle through use of mechanical fasteners. Tethers attached to the outer surface of the trim panel create difficulties in applying an exterior coating or covering over the trim panel to make it more aesthetically appealing and use of additional mechanical fasteners adds costs and additional assembly time in the manufacture of the vehicle.